Fix a tblgen problem handling variable_ops in tblgen instruction

definitions. This adds a new construct, "discard", for indicating
that a named node in the input matching pattern is to be discarded,
instead of corresponding to a node in the output pattern. This
allows tblgen to know where the arguments for the varaible_ops are
supposed to begin.

This fixes "rdar://5791600", whatever that is ;-).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51699 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 0 deletions

diff --git a/utils/TableGen/CodeGenDAGPatterns.cpp b/utils/TableGen/CodeGenDAGPatterns.cpp
index 8c46b35fa1..006c067e8f 100644
--- a/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -916,6 +916,8 @@ bool TreePatternNode::ApplyTypeConstraints(TreePattern &TP, bool NotRegisters) {
         MadeChange |= Child->UpdateNodeType(MVT::iPTR, TP);
       } else if (OperandNode->getName() == "unknown") {
         MadeChange |= Child->UpdateNodeType(MVT::isUnknown, TP);
+      } else if (OperandNode->getName() == "discard") {
+        MadeChange |= Child->UpdateNodeType(MVT::isUnknown, TP);
       } else {
         assert(0 && "Unknown operand type!");
         abort();